I think there are a couple of angles here:
- Tony Fadell, the godfather of the iPod, is now at Google—a company that is increasingly involved with hardware. cf. Motorola. And as Dan Frommer pointed out, Nest has a lot ex-Apple engineers.
- Google has been experimenting with electricity—both publicly and privately—for a long time. Relevant: nearly half of Americans’ energy bills are spent on heating and cooling.
- Google already controls the services layer for traditional internet-connected PCs. But they are skating where the puck’s going and laying strong services foundations in three emerging consumer platforms: mobile, car and home.